Ghrelin

Ghrelin is a hormone that is produced and released in the stomach. It is often refer to it as the “hunger hormone” because it increases appetite. Ghrelin also promotes blood sugar regulation, prevents muscle breakdown, and protects the heart. It is also produced in the small intestine, brain, and pancreas.

Ghrelin travels through the bloodstream to the brain, where it acts on the hypothalamus. The hypothalamus is a part of the brain, which produces hormones that regulate hunger, mood, thirst, and many other important functions within the body.

Ghrelin is often referred to as the hunger hormone because its primary role is to regulate appetite. When ghrelin activates its receptor — growth hormone secretagogue receptor — it causes an individual to eat more food and store extra fat.

In persons who are trying to lose weight or who have recently lost weight, ghrelin levels are often higher, making it challenging to maintain weight loss. I knew some persons with diabetes who participated in a 2-year weight management program. Some of them who initially lost weight slowly regained it over time. It is no doubt that weight loss was associated with increased ghrelin levels and increased hunger, which might make it difficult to keep weight off.

Ghrelin affects a person’s sleep/wake cycle, taste sensation, and reward-seeking behaviour. As it plays a role in reward processing, many experts believe higher ghrelin levels can contribute to food and alcohol misuse.

Ghrelin also has many functions in the body, including improving heart health, preventing muscle atrophy, and influencing bone metabolism. It can also stimulate gastric acid secretion and accelerate gastric emptying.

Levels of ghrelin frequently change throughout the day and are primarily controlled by food intake. Ghrelin levels usually rise when the stomach is empty and decrease once a person has eaten.

People who have obesity have higher levels of ghrelin circulating. This can lead to a continuous state of hunger and make it difficult to lose weight.

Dieting also has been known to stimulate ghrelin secretion. What is more, diets can also decrease leptin levels, which is known as the “satiety hormone.” Combined, this may make it difficult to lose weight and keep it off long term.

Interestingly, experts believe people who have undergone weight loss surgery have lower levels of ghrelin, which may make it easier to keep weight off. Ghrelin levels fall significantly following sleeve gastrectomy. This is because part of the stomach — the gastric fundus — where most ghrelin is produced is completely removed. However, this is not a consistent result.

People with certain health conditions also tend to have elevated ghrelin levels.

Ghrelin levels also may be higher during periods of stress. Higher ghrelin levels are thought to have an anxiolytic effect on the body.

Although elevated ghrelin levels are commonly perceived as unfavourable and associated with increased appetite, certain individuals may benefit from higher ghrelin levels. For instance, someone struggling to gain weight or with wasting syndrome may benefit from the appetite-stimulating effects of ghrelin.

Ghrelin administration may potentially be helpful in patients with cancer cachexia because it can help reverse weight loss and protein breakdown in catabolic states. Although short-term ghrelin administration appears to be safe and well-tolerated, we need more studies on its effectiveness and safety before recommending it.

Ghrelin levels may increase following weight loss. Decreasing levels of ghrelin in the body may help decrease a person’s appetite, prevent weight regain, or promote weight loss. However, it is important to note that changes in ghrelin alone are not sufficient to predict weight gain following weight loss in most people. Behavioural, physiological, and environmental factors also play a role in weight regain.

An individual who wants to naturally decrease ghrelin levels may want to try some of the following interventions:

1. Follow a healthy diet

People’s ghrelin levels tend to increase when on a diet and not eating enough calories. Avoiding an empty stomach and eating a nutrient-rich diet may help limit ghrelin secretion. The main elements that make up a healthy dietary pattern include:

(a) Vegetables of all types

(b) Fruits, especially whole fruit

(c) Grains, at least which half are whole grains

(d) Low fat dairy

(e) Lean protein

(f) Oils, such as olive oil and those naturally occurring in nuts and fatty fish

Some foods may also decrease ghrelin levels. Fiber-rich foods could reduce ghrelin levels.

2. Get adequate sleep

Poor sleep patterns are tied to increased ghrelin level and decreased leptin levels, leading to increased appetite and hunger. For better sleep, aim to get a minimum of 7 hours of sleep in a 24-hour period.

3. Eat more protein

Consuming high protein meals and snacks can help promote satiety and reduce ghrelin levels. In fact, many meal-related studies have shown significant reductions in hunger and increased fullness following high protein meals.

4. Limit stress

Although removing stress altogether is near impossible, studies show that high levels of chronic stress can lead to elevated ghrelin levels. In addition to signaling hunger, ghrelin may affect brain function. The exact mechanism remains unclear, and mixed findings make it difficult to draw conclusions about ghrelin’s role in stress.

Regular physical activity, adequate sleep, and practicing yoga or meditation can help minimize stress.

Thank you for reading.